Recently, in the interest of enhancement in information processing capacity, researches and studies have been conducted as to replacement with an optical transmission system in regard to telecommunication between electrical devices such as integrated circuit components. For example, in Patent Literature 1, there is disclosed an optical transmission module constructed by mounting a plurality of optoelectronic conversion devices such as light-emitting devices in an optical transmission structure having a plurality of optical waveguides extending in the direction of substrate thickness. The optical waveguides are disposed in a plurality of through holes, respectively, formed so as to pass completely through the substrate in its thickness direction.